1. Field of the Invention
The present invention relates to a travelling system of a magnetic recording/reproducing apparatus, and more particularly to an idler controlling apparatus, wherein the rotational force transmitted to a travelling system from a capstan motor is selectively supplied to a supply reel and a take-up reel for controlling the travel of a magnetic tape.
2. Description of Prior Devices
Generally, magnetic recording/reproducing devices which record or reproduce signals on or from a magnetic tape, include a drum provided with heads on a deck, a tape travelling system for transferring the magnetic tape seated on a supply reel and a take-up reel along a predetermined path, a tape loading system for applying the magnetic tape to the drum, and elements for driving the reels. Typically, such a magnetic recording/reproducing device will have a loading motor for driving the tape loading system and a capstan motor for driving the tape travelling system and reels. The inclusion of two motors tends to make the magnetic recording/reproducing device relatively large and heavy.
A recent trend has been towards small lightweight magnetic recording/reproducing devices, such as those which utilize the widely available 8 mm tape cassette. Applicants of the present invention devised a small, lightweight magnetic recording/reproducing device as disclosed in Published PCT Application WO93/12163, (corresponding to Korean Patent Application 93-5016), which is incorporated herein by reference. As disclosed in the latter publication, the deck size is highly minimized in such a manner that a tape cassette is inserted into a cassette holder having a rotary drum to perform the first loading of a magnetic tape, and the cassette holder is then closed by being pressed to fully load the magnetic tape secondly, wherein the rotary drum is completely held within an internal space of the tape cassette while the loading operation of the tape cassette is completed. According to this apparatus, power is supplied to the travelling system and loading system by means of a single capstan motor, thereby eliminating the need for two motors and reducing the size and weight of the tape deck. The invention herein pertains to an improvement for the magnetic recording/reproducing player of the type described therein.
Applicants have also devised an idler controlling apparatus suitable for the latter mentioned small type magnetic recording/reproducing apparatus as disclosed in pending U.S. patent application Ser. No. 08/280,611 (corresponding to Korean Patent Application (KPA) No. 93-14174) now U.S. Pat. No. 5,467,234, incorporated by reference herein. As shown in FIG. 1, which represents the device of the latter Patent Application, a capstan motor 2, which rotates in the forward or reverse directions in accordance with a mode control signal, is mounted on one side of the lower chassis 1. A transmission gear 4, which rotates around a shaft 4a, is brought into meshing engagement with gears 2a of the capstan motor 2 by means of a lever 3 on a bracket (not illustrated), and swings to the right or left under the control of the capstan motor and a plunger (not shown). When swung to the right, the gear 4 meshes with the gear 5 of the tape travelling system. When swung to the left, the gear 4 is meshed with a gear (not shown) of the tape loading system. The tape loading system as well as the apparatus for controlling the selective transfer of rotary power from capstan motor 2 to the loading system and the tape travelling system is fully shown in the above mentioned Published PCT application, although certain of the details shown in the PCT application are not shown herein as they are not necessary for a complete understanding of the features added by the present invention.. The tape loading system includes a ring gear 14 plus a plurality of gears (not shown) that transfer rotary power from the gear 4 to the ring gear 14. The ring gear loads the tape onto the rotary drum in a well known manner.
The magnetic tape travelling system is formed such that gear 5 rotates around a shaft 5a on the lower chassis 1. The gear 5 is brought into meshing engagement with the transmission gear 4, which transmits the rotational force of the capstan motor 2. A pulley 5b formed on the gear 5 is connected to a pulley 6a of a driven gear 6 via a belt 7. The driven gear 6 is brought into meshing engagement with an idler gear 8 connected through the upper portion of an idler lever 8a, so that the idler gear 8 swings to the right or to the left in accordance with the rotational direction of the capstan motor 2 to supply the rotational force to a take up reel 11 and a supply reel 10, both of which are installed on an upper chassis (not illustrated). The take-up reel is indirectly supplied with the rotational force via auxiliary gears 12 and 13.
A cam gear 15 rotating around a shaft 15a is installed to be brought into meshing engagement with the ring gear 14. A cam groove 15b is formed in the upper plane of the cam gear 15, and a cam follower pin 16b of lever 16 follows the cam groove as cam gear 15 rotates, thereby causing lever 16 to pivot to the right and left about shaft 16a. A pin 16c at the lower end of the cam lever 16 fits into the end of an eject lever 17, which is installed to move in the horizontal direction.
A projecting part 17a is formed on the eject lever 17 and fits into a groove 18a formed in an idler cam 18. The idler cam 18 is formed of a thin plate and is provided with a cam surface 18b. A follower pin 8b of the idler lever 8a is in contact with the cam surface 18b. The cam 18 is biased to the position illustrated by a spring 20 attached at one end to a pin 19 and at the other end to a hooking plate not shown.
In the latter travelling system, the cam gear 15 is rotated when the ring gear 14 is rotated. As a result, the cam lever 16 and eject lever 17 are moved right to left to make the idler lever 8a and the idler gear swing to the right or to the left so that the idler gear 8 is coupled to the supply reel 10 or auxiliary gears 12 and 13 in accordance with the rotational direction of the capstan motor 2. Details of this operation are found in the latter mentioned Published PCT application.
The idler controlling apparatus places the idler gear 8 and idler lever 8a in a central position when the upper chassis is being seated on the lower chassis, and swings the idler to the right or the left during the travelling of the tape between the supply and take up reels. The direction of the swing and the reel which is controlled is dependent upon the rotational direction of the capstan motor.
Because of the potential for movement of the idler lever and idler gear, if the idler lever and gear are free to move during the process of seating the upper chassis on the lower chassis, the freely moving gear may interfere with the seating process. Therefore it is necessary to limit such movement during the seating process.